Continental shelf of Brazil

The continental shelf of Brazil is the seabed and subsoil underlying its jurisdictional waters, where the country has sovereign rights over natural resources as a party to the United Nations Convention on the Law of the Sea (UNCLOS). An area of 3.5 million square kilometers as far as 200 nautical miles (370 kilometres) from baselines along the coast is internationally recognized as such. From 2004 to 2018 Brazil submitted a series of extended continental shelf proposals beyond the 200 nautical mile line to the Commission on the Limits of the Continental Shelf (CLCS). The proposed extended shelf measures 2,094,656.59 km². A final understanding has yet to be reached with the CLCS, and therefore the outer limits of the extended shelf are still not final and binding. The Brazilian Navy includes the continental shelf in its concept of a "Blue Amazon".

The concept of a continental shelf was introduced to Brazilian law in 1950, although lacking a clear limit. In the beginning of the following decade, it was the point of contention in the "Lobster War" with France. The 1970 extension of the territorial sea to 200 nautical miles from the coast subsumed the shelf's distinct existence, as the territorial sea includes the seabed and subsoil. When the UNCLOS came into force in 1994, the territorial sea was reduced and the shelf's outer limit now matched that of the exclusive economic zone (EEZ). Offshore oil drilling began in the continental shelf over this period and since then it provides most of Brazil's fossil fuel production.

In order to substantiate its proposals of a continental shelf beyond the 200-nautical mile line, since the late 1980s the Brazilian Navy, Petrobras and the country's scientific community joined in the Brazilian Continental Shelf Survey Plan (LEPLAC) to retrieve hundreds of thousands of kilometers of geological profiles in the area. In 2007 the CLCS only accepted part of the Brazilian proposal and a new cycle of surveys began in response. Economic interest in the region grew after the discovery of fossil fuel deposits in the pre-salt layer of underwater sedimentary basins, thanks to which Brazil became the world's 8th largest crude oil and lease condensate producer in 2023. Revised proposals are larger and in 2018 covered the mineral-rich Rio Grande Rise.

Geologically, Brazil's legal continental shelf mostly corresponds to a divergent continental margin formed by the split between South America and Africa, with a well-defined shelf, slope and rise. It is at its widest off the Northern coast, where the Amazon River forms one of the world's largest submarine fans. The margin narrows through the Northeast and widens again south of the Abrolhos Bank. The São Paulo Plateau, which is the largest marginal plateau in the Brazilian coast, contains its two richest oil basins (Campos and Santos). Beyond fossil fuels, the continental margin also has mineral reserves of coal, gas hydrates, aggregates, heavy mineral sands, phosphorite, evaporites, sulphur, cobalt-rich ferromanganese crusts, polymetallic sulfides and polymetallic nodules, which are almost entirely untouched by undersea mining.